- Build the model, and assign constants to the converters, and constant initial values to the stocks, whose values you want to manipulate over a series of sensitivity runs.
-
In Edit mode 
, click a blank part of the model to open the Properties panel for the model, then select the Sensitivity tab 
. The Sensitivity panel will open.
- Select either "All combinations" or "Specific number of runs", based on your needs. "All combinations" is normally used only when all your distribution choices will be Incremental or Ad-Hoc. If you select "Specific number of runs", enter the number (for example, 5). When "All combinations" is selected, each variable will have a number of runs specified. The total number of runs will be the product over all variables.
-
Select the variables you want to control during the sensitivity runs. Add an entry by clicking on the 
button, then choose.
Tell me how
Choose a variable in one of the following ways:
- In the Variable box, begin typing the name of the variable you want to add. A list of matching variables will appear. Click the variable you want, (or arrow to it) and press Enter.
- Click the Find icon at the top of the Properties panel and begin typing the name of the variable you want to add. A list of matches will appear. Drag the name you want to the Variable box.
- Ctrl-drag (⌘-drag on Mac) directly from the model to the Variable box.
- Select a distribution from the dropdown. The fields that need to be filled in will depend on your selection. For more information about selecting these options, see Selecting sensitivity analysis variation types.
- For random distributions, fill in the seed and distribution parameters. The distribution parameters are the same as those for the builtins, as described in Statistical builtins. If you selected "All combinations" previously, in step 3, enter the number of runs.
- For the Ad-Hoc distribution, enter a comma separated list of numbers to be used.
- For an Incremental distribution, enter the starting and ending values. If you selected "All combinations" previously, in step 3, then you can also specify the number of runs to be made.
- Repeat step 4 for each variable you want.
-
Make sure that the Number of Runs is bigger than 0 (if it's 0, sensitivity runs won't be available).
Tip: You can create comparative graphs and tables to view results for the desired variables. You can also see them in the Results panel by opening it and clicking on the variable you want to see the results for (as long as you've selected "Keep all variable results" in the Model Settings Properties Panel).
- You can click S-Run in the Run toolbar to start the sensitivity run, or use Run Sensitivity from the model menu.
- After a sensitivity run, if you click on the S at the top of comparative tables or graphs, it will display the sensitivity values used in each of the runs listed. This only works for comparatives created before the sensitivity run was made.